The question that i have for all of you 3rd gen die hards is: I just recently blew my motor in my 87 IROC-Z, the next day i went and purchased the ZZ4 short block( good choice ), now the question is, I also just purchased the LT4 hot cam kit, that comes with the cam, roller rockers, valve springs and the retainers, now all of that stuff should work on the ZZ4 short block along with my ported heads and my TPI unit?
I have heard that it will and now that I bought all of the stuff someone just told me that it will not work, so that is why I'm turning to the professionals for the answer, all of the input that I get is greatly appreciated and i trust the info that is giving to me. Thanx for helping a 3rd gen member out!

 

depends on what he means by not working. will everything bolt on and run yes. will you need to tune it with a prom and other goodies to maximize performance, yes. one guy in our club put a complete zz4 in his '87 GTA. used all his stock stuff. ran lean. put an AFPR on, turned it to 52 psi. problem solved.

 

Since you purchased the short block only, I am assuming you did not get the heads. If you got the heads, they already come with the LT4 springs, if you're using your stock heads, the LT4 springs will fit, just make sure the installed height is correct.......

 

Did the same thing to my 87 vette. Absolutely will work!! Got a little over 400 rwhp.

 

It will work, with some additional work. You need PROM tuning though, the LT4 hot cam is too much for the stock PROM. You'll run like a pig until you tune it up.

I don't know if you've got the time or the money, but if your heads need more work, then now's the time to do it. As well as modifying your intake. You'd need that as well, because the power band of the hot cam is way too high for the stock TPI system. You'd need a new intake manifold, or a completely hogged out stocker (though there's not much meat on the stockers), bigger runners (hogged out SLP runners should be OK but not optimal) and a ported plenum. You'll probably need headers too if you don't have some.

If that's a bit too much, I'd ask you to reconsider the LT4 hot cam and pick a milder cam (zz4 cam for example). You'd have a mismatched cam if you don't open up the intake and exhaust, and will likely be disappointed.

Or, if you expect that and will do the other mods later, then that's OK too. The important thing after the swap, is the tuning.

 

I understand what you are saying about the restriction for the exhaust and the intake. I have already talked to a buddy and he is going to be porting the runners, intake and the heads more then they already are, like any other person I also have a budget and I broke it when i purchased all of the motor parts. The plendum is completely gutted and I do have plans on putting some headers on the vehicle, for the exhaust right now I have a Borla that is 3 inches and I have the open plate in.
I plan on doing everything that is needed to do for tuning the motor, I'm also putting in a stall converter and plan on having the chip burned to match the cam, heads and the stall converter to asure that everything is correct. This will not be a half a$$ed motor, I plan on going all out and having it done right. I appreciate all of the input guys and keep it coming!!!!!
There is just one more thing I have to ask, what do u think the motor will do in the quarter. I also have gears, shift kit, MSD ignition all around and all of the other stuff that I have already said, I'm really intrested on hearing what you have to say, hopefully I hear some good numbers!!!!